The invention relates to a switching arrangement for converting digital signals, more particularly PCM signals, supplied by a signal output device into analog signals to be applied to a telephone station of a telecommunication network and for converting analog signals supplied by the telephone station into digital signals, more particularly PCM signals, to be applied to a signal receiving device through a converter circuit.
Switching arrangements of the type mentioned above are known in the art (French Pat. No. 2,133,522; "IBM-Technical Disclosure Bulletin," Volume 10, No. 9, February 1968, pp. 1372, 1373). A disadvantage of these switching arrangements is the fact that even in their idle condition current is consumed by the converter circuits when no conversion functions need to be performed.
It is therefore an object of the invention to provide means for reducing the current consumption in a switching arrangement of this type in the event that no conversion processes are to be carried out.
In accordance with the invention, the above and other objects are achieved by connecting the converter circuit over a switch to its working supply voltage generator. An enabling signal causes the switch to close in the event a detector circuit, which receives and corrects the digital signals to be converted into analog signals, detects the appearance of at least one of the pulses making up the digital signals. The switch is also enabled in the event the associated telephone station is in its operating condition. The invention ensures that no unnecessary current consumption takes place during the periods when no conversion processes are to be carried out.